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Biomedical subjects

F Damiani

Publications and source records attributed to F Damiani.

10 recordsLinked to original sources
PubMed2002

Spermiogenesis in the vermetid gastropod Dendropoma petraeum (Gastropoda, Prosobranchia).

The structure and maturation of the male gonad of the Mediterranean vermetid gastropod Dendropoma petraeum are described. Histological sections of the gonads were made throughout development and gonad activity was monitored at regular monthly intervals. During the autumn months the gonad is very small and is surrounded by a large quantity of connective tissue; it becomes more voluminous from December to August, with the highest growth peak in springtime. The stages of spermatogenesis were also observed and described.

Animals↗
PubMed2000

Biocompatibility of alloys used in orthodontics evaluated by cell culture tests.

The cytotoxicity of the most common alloys used in orthodontic appliances was determined by cell culture testing. Human gingival fibroblasts were cultured on 304 and 316 stainless steel, on brazing alloy composed of palladium (Pd), copper (Cu), and silver (Ag), and on plastic substrate (control). Studies were carried out with SEM and radiolabeled precursor incorporation. Cells were cultured in MEM without serum but with the addition of (3)H-thymidine to evaluate cell proliferation and (3)H-glucosamine to evaluate glycosaminoglycan (GAG) synthesis and secretion in the culture medium. Moreover, gingival fibroblasts were cultured in the presence of some metal ions generally released by orthodontic appliances to evaluate the cytotoxic effects of single ions. Morphologic observations with SEM and radiolabeled incorporation studies showed that 304 and 316 stainless steel were more biocompatible than the brazing alloy. Among the metal ions tested, Ag and Pd, constituents of the brazing alloy, showed the highest cytotoxicity.

Alloys↗
PubMed1999

Ion release from orthodontic appliances.

OBJECTIVE: The microbiological and enzymatic characteristics of the oral cavity would seem to provide a suitable environment for the corrosion of metals. We assayed the release of metal ions from one orthodontic appliance which included two 304 and 316 steel molar bands, ten 316 steel brackets, one nickel-titanium archwire and a brazing alloy to connect the elements of molar bands and brackets. METHODS: The orthodontic appliance was dipped in both inorganic (pH 3.5-6.5) and organic acid solutions (w/v 1% each of tartaric, citric and ascorbic acid at pH 2.2 or 1.5% each of lactic and acetic acid at pH 2.5). The release of nickel (Ni), chromium (Cr), copper (Cu), silver (Ag) and palladium (Pd) was determined using an atomic absorption spectrophotometer Varian AA 10. RESULTS: The release of Ni, Cr and Cu was markedly less at pH 6.5 than at pH 3.5 at all time points in acid solution. Daily release/single appliance after the first day decreased. Contrary to expectations, appliances immersed in organic acid solutions at pH 2.2 or 2.5 after 28 days generally released an amount of ions similar to that observed in inorganic acid solution at pH 3.5, with the exception of Cu. Release of silver and palladium, two metals present in the brazing alloy, proved to be very low (approximately 0.2 microgram after 28 days). CONCLUSIONS: The daily release of Ni, Cu and Cr by an orthodontic appliance in acid pH, particularly favourable to corrosion, was well below that ingested with a normal daily diet. It is therefore concluded that the quantities of metal ions released in our experimental conditions should not be cause for concern in utilising the appliance.

Chromium↗
PubMed1996

[Computerized multiple-choice questions: an efficacious method of evaluation in medical instruction?].

To evaluate the efficacy of Multiple Choice Questions (MCQ) as an evaluation tool in medical education, were analyzed the responses to 80 MCQ delivered by 300 physicians working in emergency departments and following a course on Basic and Advanced Life Support. Pre- and post-test were administered using a dedicated computer application running on PC. Students' scores were high and demonstrated both course and test validity. More than 95% of the students used the computer application without interface difficulties. However, some limits of MCQ were individuated: first, misinterpretation of some questions, especially when two or more similar answers were presented; from the other side, the student's personal experiences during the course practice could influence student's responses bringing him to different conclusions on respect to the instructor. These difficulties should be kept in mind in the development of a MCQ session, and students should have the possibility to give to the instructor a feedback of problems encountered during the course. This is especially important when MCQ are the sole evaluation technique.

Adult↗
PubMed1996

Evidence of induced non-tolerance in HLA-identical twins with hemoglobinopathy after in utero fetal transplantation.

Fetus-to-fetus transplantation has been suggested for the treatment of hemoglobinopathies in utero. However, dissimilar results have to date been obtained by different groups. We describe a case in which fetus-to-fetus transplantation in HLA-identical twins was performed at the 19th week of gestation by infusion of 0.8 ml of fetal blood from normal to beta-thalassemia affected fetus with the main aim of inducing tolerance. No evidence of engraftment, determined by KM19 polymorphism, was present after 2 years of the procedure. Moreover, an alloreactive cytotoxic T lymphocyte precursor (CTLp) study of affected fetus vs donor and other different stimulators showed that immunization vs tolerance was the real effect of the procedure.

Adolescent↗
PubMedDate not supplied

[Transient pseudohypoaldosteronism secondary to congenital malformation pathology of the urinary tract (valves of the posterior urethra): a report of a case with elements of a physiopathological nature].

A case of secondary transient pseudohypoaldosteronism (PHA) in a three-month-old infant who had arrived in emergency conditions is reported. Clinically the patient presented dehydration associated with salt loss, metabolic acidosis, severe hyperkalemia, markedly elevated levels both of plasma renin activity and aldosterone concentration. Biochemical and instrumental tests and clinical evolution have given reason to consider it as a case of transient PHA, secondary to an obstructive uropathy (PUV) with urinary infection. Secondary forms of PHA have frequently been documented in young infants with urinary tract infection associated with both obstructive and non obstructive uropathy. After medical or surgical therapy the abnormalities quickly disappear. This reported case suggests that the pediatrician-neonatologist dealing with a young infant with obstructive uropathy should not only consider the surgical treatment but also the medical one, in the light of the associated physiopathological aspects.

Diagnosis, Differential↗